Conventionally, a technology of identifying the position of a three-dimensional object by combining a range sensor for acquiring three-dimensional information of the object and a camera for acquiring a two-dimensional image thereof has been known (see PTL 1, for example).
In the technology of PTL 1, a two-dimensional image acquired by a camera is processed to detect an image of an object in the two-dimensional image and acquire two-dimensional positional information of the object, and based on the acquired two-dimensional positional information, the three-dimensional position and the posture of the object are calculated from three-dimensional information.